At occurrence of a gas leak, a slight temperature change takes place at a location where the leakage gas hangs. Remote gas sensing using an infrared camera is known as a technique for sensing gas using this principle.
As gas sensing using infrared images, for example, Patent Literature 1 discloses a gas leak detection apparatus including: an infrared camera for photographing an inspection target region; and an image processing unit for processing an infrared image photographed by an infrared camera, in which the image processing unit includes a fluctuation extraction unit for extracting dynamic fluctuation due to a gas leak from a plurality of infrared images aligned in time series.
When a gas leak is sensed in a plant or the like, an engineer needs to visit a gas leak position and repair the gas leak. In gas sensing using an infrared image, an image including a gas region image illustrating a region in which the leakage gas hangs is displayed on a display unit. The engineer searches for a gas leak position using the gas region image as a clue. Since the gas region image is a surface and the gas leak position is a point, specifying the gas leak position from the gas region image is not easy and takes time. Particularly in a case where the area of the gas region image is wide, it is difficult to specify the gas leak position from the gas region image. This increases a demand for a technique capable of estimating the gas leak position from the gas region image.